Kosmos 1867 (Russian: Космос 1867) is a nuclear powered radar ocean reconnaissance satellite (RORSAT) that was launched by the Soviet Union on July 10, 1987. It was put into an orbit of about 800 km (500 mi). Its mission was to monitor the oceans for naval and merchant vessels, and had a mission life of about eleven months.[1][2][3][4]

Kosmos 1867
Illustration of Cosmos 1818 and Cosmos 1867.jpg
Kosmos 1867
Mission typeRadar ocean surveillance
COSPAR ID1987-060A Edit this at Wikidata
SATCAT no.18187
Mission duration~ 11 months
Spacecraft properties
Spacecraft typePlazma-A
Launch mass1,500 kilograms (3,307 lb)
Start of mission
Launch dateJuly 10, 1987, 15:36:00 (1987-07-10UTC15:36Z) UTC
Launch siteBaikonur 90
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude797 kilometres (495 mi)
Apogee altitude813 kilometres (505 mi)
Inclination65.01 degrees
Period100.8 minutes
EpochApril 14, 2014 UTC 21:26:10.75


Kosmos 1867 was launched on July 10, 1987, on a Tsyklon-2 rocket from the Baikonur Cosmodrome. It was put into an orbit about 800 km (500 mi) above the Earth's surface at an inclination of 65° and a period of 100.8 minutes. The satellite had a mission life of about 11 months.[1][2][4]

The satellite was powered by TOPAZ 1 nuclear reactor. This reactor was cooled by liquid sodium-potassium (NaK) metal, and used a high-temperature moderator containing hydrogen and highly enriched fuel. The reactor produced electricity using a thermionic converter. The satellite used a Plazma-2 SPT Hall-effect thruster for propulsion.[3][4]

The mission of Kosmos 1867 was to search the oceans for naval and merchant vessels. Unlike earlier Soviet RORSAT satellites, Kosmos 1867 and its twin, Kosmos 1818, were launched into high orbits. This reduced the likelihood of mishaps resulting in uncontrolled re-entry of radioactive material, as had occurred with Kosmos 954 and Kosmos 1402, which showered the Earth with radioactive debris.[4]

In 1992, Kosmos 1867 had a visual magnitude of approximately 3.3.[5]

Kosmos 1867 had become damaged, resulting in several fragments of space debris. It is suspected that the coolant tube had leaked NaK metal, in a manner similar to Kosmos 1818 in 2008.[6] On April 8, 2014, the US Space Surveillance Network reported that 11 new objects were detected, and 24 more objects ware reported on April 15, 2014.[citation needed] The coolant tube of Kosmos 1867 may have cracked due to thermal stresses by repeated solar heating, or by an impact.


  1. ^ a b "Cosmos 1867". Real Time Satellite Tracking. N2YO.com. Retrieved 2009-01-25.
  2. ^ a b "Cosmos 1867". NSSDC Master Catalog Search. NASA. Retrieved 2009-01-24.
  3. ^ a b Broad, William J. (January 15, 1989), "Russians Disclose Satellites Carry New Reactor Type", New York Times
  4. ^ a b c d "New Debris Seen from Decommissioned Satellite with Nuclear Power Source" (PDF). Orbital Debris Quarterly News. NASA. 13 (1). January 2009. Retrieved 18 June 2018.
  5. ^ "Spacecraft Particularly Suited for International Participation: Category I". SPACEWARN Bulletin Number 461. NASA. March 25, 1992. Retrieved 25 January 2009.
  6. ^ "Flurry of Small Breakups in First Half of 2014" (PDF). Orbital Debris Quarterly News. NASA. 18, Issue (3). July 2014. Retrieved 18 June 2018.